TWI544585B - Semiconductor device and flexible printed circuit - Google Patents

Description

Semiconductor device and flexible printed circuit

The present invention relates to a semiconductor device and a flexible printed circuit.

A flexible printed circuit in which a cover film is provided on the surface is known as disclosed in Japanese Laid-Open Patent Publication No. 191170. The following flexible printed circuit is also referred to as "FPC" for Flexible Printed Circuit. According to the FPC of the above publication, a base film, a metal foil, and a cover film as a surface covering layer thereof are laminated. For this laminate construction, the predetermined solder portion is holed to form the through hole into a predetermined shape. A lead terminal of the mounting component is inserted into the through hole for soldering.

The molten solder is about to flow out from the lead terminal to the outer adjacent portion. As a result, there is a problem of a bridge-like short circuit (hereinafter referred to as "solder bridge short circuit") between the solders flowing into the adjacent solder portions. In this regard, according to the above publication, since the three cover films are overlapped, the total thickness is sufficiently thick to prevent the inflow of solder between the adjacent portions. As a result, the occurrence of a bridge short circuit can be prevented.

[advance technical documents]

[Patent Document 1] Japanese Patent Publication No. 191170

[Patent Document 2] Japanese Patent Publication No. 170029

[Patent Document 3] Japanese Patent Publication No. 2007-66946

[Patent Document 4] Japanese Patent Publication No. 2008-10798

[Patent Document 5] Japanese Patent Publication No. 2008-91557

[Patent Document 6] Japanese Patent Publication No. 2010-153534

According to the flexible printed circuit of the above publication, the short circuit between the plurality of solder portions adjacent to each other in the planar direction of the flexible printed circuit is suppressed. On the other hand, the inventors of the present invention paid attention to the problem that the semiconductor flows out in the thickness direction of the flexible printed circuit in addition to the problem of the solder flowing out in the planar direction.

A semiconductor device includes a frame portion and a lead terminal extending from the frame portion. A through hole is formed in the flexible printed circuit, and the lead terminal is inserted into the through hole from one side of the flexible printed circuit. The frame portion is located on one surface side of the flexible printed circuit, and the lead terminal is soldered from the other surface side of the flexible printed circuit to the through hole.

At this time, when the solder adhering to the surface of the lead terminal is conducted through the through hole, a gap flows between the flexible printed circuit and the surface of the lead terminal. As a result, the solder flows out to the frame portion, and the solder adheres to the surface of the frame portion.

The present invention has been made to solve the above problems, and has an object of providing a semiconductor device and a flexible printed circuit that suppress adhesion of solder to a frame portion.

A semiconductor device according to a first aspect of the present invention, comprising: a semiconductor device body including a frame portion that houses a semiconductor element therein and from above a terminal for extending the frame body; and a flexible printed circuit including a substrate body on which the wiring is disposed and a cover film disposed on the substrate body, and mounting the semiconductor device body; wherein the substrate body can be bent, including a mounting surface on the main body side of the semiconductor device, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; the terminal is inserted into the through hole; and the cover film is disposed to an edge of the through hole Further, the inner side covers the periphery of the terminal passing through the through hole, and is provided on the mounting surface side; and the terminal is welded to the through hole from the back side.

A semiconductor device according to a second aspect of the present invention, comprising: a semiconductor device body including a frame portion that houses a semiconductor element therein and a terminal extending from the frame portion; and a flexible printed circuit including a substrate body on which the wiring is provided And mounting the semiconductor device body; wherein the substrate body is bendable, and includes a mounting surface facing the semiconductor device body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; The terminal is inserted into the through hole; the terminal is soldered to the through hole from the back side; the spacer surface is further provided with a spacer layer; and the spacer layer is interposed between the flexible printed circuit and the frame portion In order to prevent the solder fillet of the solder from reaching the surface of the frame portion.

A flexible printed circuit according to a third aspect of the present invention includes a substrate body on which wiring is provided, and a cover film provided on the substrate body; wherein the substrate body is mounted with a semiconductor device body; and the substrate body can be bent And a mounting surface facing the semiconductor device main body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; and the cover film is provided on the mounting surface side to cover the through hole.

A flexible printed circuit according to a fourth aspect of the present invention includes a substrate body on which wiring is provided, and a cover film provided on the substrate body; wherein the substrate body is mounted with a semiconductor device body; and the substrate body can be bent a mounting surface facing the semiconductor device main body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; and the cover film is disposed on the mounting surface side and includes a pass The opening of the small diameter of the hole partially covers the through hole.

According to the present invention, solder adhesion can be suppressed on the frame portion of the semiconductor device body to be mounted in the flexible printed circuit.

10‧‧‧Semiconductor device

21‧‧‧Flexible printed circuit

22‧‧‧Semiconductor device body

22a‧‧‧ Frame Department

22b‧‧‧Low-melting glass

22c‧‧‧ recess

23‧‧‧Lead terminal

24‧‧‧ solder

25‧‧‧ Cover film

25h‧‧‧through hole

27‧‧‧Flexible substrate body

27a‧‧‧Assembled surface

27b‧‧‧Back

27c, 27d‧‧‧through points

28a‧‧‧Conductor layer

28b‧‧‧Conductor layer

31‧‧‧Flexible printed circuit

35‧‧‧ Cover film

35a‧‧ Cover film

35b‧‧‧ Cover film

35h‧‧‧through hole

41‧‧‧Flexible printed circuit

44f‧‧‧ solder fillet

45‧‧‧ Cover film

45a‧‧‧ openings

46‧‧‧ spacer

46a‧‧‧through hole

48a, 48b‧‧‧ conductor layer

110‧‧‧Semiconductor device

124‧‧‧ solder

125‧‧‧ Cover film

125a‧‧‧ openings

210‧‧‧Semiconductor device

310‧‧‧Semiconductor device

321‧‧‧Flexible printed circuit

D1‧‧‧ thickness

D2‧‧‧ thickness

D3‧‧‧ Height

G‧‧‧ gap

TH1, TH2‧‧‧ through hole

ψ 1‧‧‧diameter

ψ 2‧‧‧diameter

ψ 3‧‧‧diameter

ψ A‧‧‧ diameter

1 is a view showing a semiconductor device and a flexible printed circuit diagram according to a first embodiment of the present invention; and FIG. 2 is a view showing a semiconductor device and a flexible printed circuit diagram according to a second embodiment of the present invention; [Fig. 3] The semiconductor device and the flexible printed circuit diagram of the third embodiment of the present invention are shown; and the fourth embodiment shows a semiconductor device and a flexible printed circuit diagram of a comparative example shown to explain the effects of the embodiment of the present invention.

First embodiment

Fig. 1 is a view showing a semiconductor device 10 and a flexible printed circuit 21 according to a first embodiment of the present invention. Figure 1 shows a semiconductor device 10 and a flexible print A cross-sectional view of the brush circuit 21. The semiconductor device 10 includes a flexible printed circuit 21 and a semiconductor device body 22. The semiconductor device body 22 is, for example, a high-speed optical communication device.

The semiconductor device body 22 includes a frame portion 22a and lead terminals 23 extending from the frame portion 22a. For example, in the case of a CAN package or the like, the frame portion 22a is a shaft. Inside the frame portion 22a, a semiconductor element or the like is housed. The lead terminal 23 is electrically connected to a metal wire via a circuit element inside the frame portion 22a.

Each of the frame portion 22a and the lead terminal 23 is formed of a conductive material such as metal, and an insulating layer is appropriately present between the frame portion 22a and the lead terminal 23. Further, the frame portion 22a may be formed of a non-insulating material such as a model resin. The frame portion 22a includes a concave portion 22c on the side surface of the fitting surface 27a, and the lead terminal 23 extends from the bottom surface of the concave portion 22c.

The flexible printed circuit 21 includes a flexible substrate body 27 on which wiring is provided, and a cover film 25 provided on the flexible substrate body 27. In the flexible printed circuit 21, the semiconductor device body 22 is mounted.

The flexible substrate body 27 is a base film that can be bent. The flexible substrate body 27 includes a mounting surface 27a facing the semiconductor device body 22 side and a back surface 27b opposite to the mounting surface 27a. The flexible substrate body 27 includes a conductor layer 28a on the mounting surface 27a and a conductor layer 28b on the back surface 27b.

The flexible substrate body 27 includes through holes 27c and 27d. The through holes 27c and 27d penetrate the mounting surface 27a and the back surface 27b to form through holes TH1 and TH2. In the through hole TH1, a conductor layer is also provided on the wall surface of the through hole 27c, and the conductor layer 28a and the conductor layer 28b are electrically connected. On the other hand, in the through hole TH2, the conductor layer 28a It is electrically disconnected from the conductor layer 28b.

The through holes TH1, TH2 have a diameter ψ 2. The lead terminal 23 has a diameter ψ 1. The relationship of these paths is ψ 1<ψ 2.

The lead terminals 23 are inserted into the through holes TH1 and TH2, respectively. The threaded lead terminal 23 penetrates the cover film 25, and a through hole 25h is formed in the cover film 25.

Since the lead terminal 23 is punctured in the cover film 25 in the non-acupoint state, the cover film 25 contacts the periphery of the lead terminal 23. As the cover film 25, various well-known materials used as the cover film can be used, but it is preferable to form the material in which the leading end of the lead terminal 23 can easily penetrate.

Further, the lead terminal 23 inserted into the through hole TH2 is connected to the low melting point glass 22b in the frame portion 22a.

According to the above configuration, the cover film 25 covers the periphery of the lead terminal 23 passing through the through holes TH1, TH2, and is provided on the side of the mounting surface 27a. Generally, the cover film 25 is provided in order to avoid adhesion of the solder 24 to unnecessary portions on the surface of the flexible printed circuit 21. In the present embodiment, a portion of the through holes TH1, TH2 is provided or the through holes TH1, TH2 are plugged while being disposed around the through holes TH1, TH2.

The lead terminal 23 is welded to the through holes TH1, TH2 from the side of the back surface 27b.

According to the semiconductor device 10 and the flexible printed circuit 21 of the first embodiment described above, since the cover film 25 can suppress the outflow of the solder 24, the adhesion of the solder 24 to the frame portion 22a can be suppressed.

Fig. 4 is a view showing a semiconductor device 310 and a flexible printed circuit 321 of a comparative example shown to explain the effects of the embodiment of the present invention. In the semiconductor device 310, the replacement flexible printed circuit 21 is a flexible printed circuit 321, Except for this, it has the same configuration as the semiconductor device 10 of the first embodiment. The flexible printed circuit 321 and the replacement cover film 25 are the cover film 125, and in addition to this, have the same configuration as the flexible printed circuit 21 of the first embodiment.

In the flexible printed circuit 321 of the comparative example, the cover film 125 on the mounting surface 27a side has a diameter opening 125a larger than the through holes TH1 and TH2 directly under the through holes TH1 and TH2.

With the cover film 125, the solder outflow prevention effect of the cover film 25 of the first embodiment cannot be obtained. Therefore, as indicated by the symbol SH in Fig. 4, the solder 124 contacts the surface of the frame portion 22a. In particular, in the semiconductor device body 22, the frame portion 22a is a conductor, and there is a problem that a short circuit (electrical short circuit) occurs between the conductor layer 28a and the conductor layer 28a.

In this regard, according to the first embodiment, the cover film 25 blocks the solder 24 in the through holes TH1, TH2, and the outflow of the solder 24 can be suppressed, and the adhesion of the solder 24 to the frame portion 22a can be suppressed.

Second embodiment

Fig. 2 is a view showing a semiconductor device 110 and a flexible printed circuit 31 according to a second embodiment of the present invention. Fig. 2(a) is a cross-sectional view showing the semiconductor device 110 and the flexible printed circuit 31. The semiconductor device 110 has the same structure as the semiconductor device 10 of the first embodiment except that the flexible printed circuit 21 is a flexible printed circuit 31.

The flexible printed circuit 31 and the replacement cover film 25 are the cover film 35, and in addition to this, have the same configuration as the flexible printed circuit 21 of the first embodiment. Therefore, in the following description, the same or corresponding configurations as those of the first embodiment are denoted by the same reference numerals, and the differences from the first embodiment are The center explained that common items were omitted and the explanation was not simplified.

The cover film 35 includes a cover film 35a which is provided to cover the conductor layer 28a on the mounting surface 27a side, and a cover film 35b which is provided on the back surface 27b side so as to cover the conductor layer 28b. The cover film 35a is provided on the side of the mounting surface 27a, and has a through hole 35h directly below the through holes TH1, TH2.

The through hole 35h has a smaller diameter than the through holes TH1, TH2, and the cover film 35a partially covers the through holes TH1, TH2. A gap is provided between the surface of the cover film 35 that penetrates the hole 35h and the surface of the lead terminal 23. This gap is below 25 micrometers (μm).

Fig. 2(b) is an enlarged view of the vicinity of the through hole 35h in the semiconductor device 110 and the flexible printed circuit 31 of the second embodiment of the present invention. The diameter ψ A of the through hole 35h is slightly larger than the diameter ψ 1 of the lead terminal 23, and a very small gap g is provided between the surface of the through film 35h in the cover film 35 and the surface of the lead terminal 23. The gap g is half the difference between the diameter ψ 1 and the diameter ψ A . In the second embodiment, this gap g is below 25 microns.

Since the cover film 35 can suppress the outflow of the solder 24, it is possible to suppress the adhesion of the solder 24 to the frame portion 22a. Since the gap is below 25 μm, the solder 24 remains between the lead terminal 23 and the cover film 35 due to the surface tension. Therefore, the through hole 35h for passing through the lead terminal 23 is provided in the cover film 35a, and the outflow of the solder can also be suppressed. Further, since the through hole 35h is provided in advance, there is an advantage in terms of productivity and the like.

Third embodiment

Fig. 3 is a view showing a semiconductor device 210 and a flexible printed circuit 41 according to a third embodiment of the present invention. Semiconductor device 210 replaces flexible printed circuit 21 is a flexible printed circuit 41, and in addition to this, has the same configuration as that of the semiconductor device 10 of the first embodiment.

The flexible printed circuit 41 has the replacement cover film 25 as the cover film 45, the replacement conductor layers 28a, 28b as the conductor layers 48a, 48b, and the spacer layer 46, which has the same function as the flexible printed circuit 21 of the first embodiment. Construction. Therefore, in the following description, the same or corresponding components as those of the first embodiment will be described with the same reference numerals, and the description will be simplified with respect to the differences from the first embodiment, and the description will be simplified or omitted.

The cover film 45, unlike the cover film 25 of the first embodiment and the cover film 35 of the second embodiment, has a diameter opening 45a larger than the through holes TH1, TH2 directly under the through holes TH1, TH2.

A spacer layer 46 is further provided on the cover film 45 on the side of the mounting surface 27a. The recess 22c has a height d3, and the spacer layer 46 has a thickness d2. The total of the thickness d2 and the height d3 is larger than the height of the solder fillet 44f. Further, in the spacer layer 46, a through hole 46a is provided directly below the through holes TH1 and TH2.

The diameter ψ 3 of the through hole 46a is larger than the individual diameters of the through holes TH1, TH2. In the present embodiment, the diameter ψ 3 of the through hole 46a coincides with the width of the concave portion 22c. Further, the thickness d2 of the spacer layer 46 is substantially the same as the thickness d1 of the flexible printed circuit 41, but the design d2 may be larger than d1.

Similarly to the first embodiment, the lead terminals 23 are inserted into the through holes TH1, TH2, and the lead terminals 23 are soldered from the back surface 27b side to the through holes TH1, TH2.

According to the third embodiment, by providing the spacer layer 46, the solder fillet 44f is prevented from reaching the bottom surface of the recess 22c of the frame portion 22a, and the space between the flexible printed circuit 41 and the frame portion 22a can be separated. Thereby, the solder 44 can be suppressed It is brought to the frame portion 22a.

10‧‧‧Semiconductor device

21‧‧‧Flexible printed circuit

22‧‧‧Semiconductor device body

22a‧‧‧ Frame Department

22b‧‧‧Low-melting glass

22c‧‧‧ recess

23‧‧‧Lead terminal

24‧‧‧ solder

25‧‧‧ Cover film

25h‧‧‧through hole

27‧‧‧Flexible substrate body

27a‧‧‧Assembled surface

27b‧‧‧Back

27c, 27d‧‧‧through points

28a, 28b‧‧‧ conductor layer

TH1, TH2‧‧‧ through hole

ψ 1, ψ 2‧‧‧ diameter

Claims (11)

A semiconductor device comprising: a semiconductor device body including a frame portion accommodating a semiconductor element therein; and a terminal extending from the frame portion; and a flexible printed circuit including a substrate body on which the wiring is disposed and a cover disposed on the substrate body a semiconductor device according to the present invention, wherein the substrate body is bendable, and includes a mounting surface facing the semiconductor device main body side, a back surface opposite to the mounting surface, and a through surface of the mounting surface and the back surface a through hole; the cover is inserted into the through hole; the cover film is disposed on an inner side of the through hole and covers a periphery of the terminal passing through the through hole, and is disposed on the mounting surface side; and the terminal is from the back surface The side is welded to the above through hole. The semiconductor device according to claim 1, wherein the cover film contacts a periphery of the terminal. The semiconductor device according to claim 1 or 2, wherein the cover film has a gap with a surface of the terminal; and the gap is 25 μm or less. The semiconductor device according to claim 1 or 2, wherein a spacer layer is further provided in the cover film. The semiconductor device according to claim 4, wherein the thickness of the spacer layer is equal to or greater than a thickness of the flexible printed circuit. A semiconductor device comprising: a semiconductor device body including a frame portion that houses a semiconductor element therein and a terminal extending from the frame portion; and a flexible printed circuit including a substrate body on which the wiring is disposed, and mounting the semiconductor device body; wherein the substrate The main body may be bent, and includes a mounting surface facing the semiconductor device main body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; the terminal is inserted into the through hole; the terminal is from the above The back side is soldered to the through hole; the mounting surface side is further provided with a spacer layer; and the spacer layer is interposed between the flexible printed circuit and the frame portion to prevent the solder fillet of the solder from reaching the frame The surface of the body. The semiconductor device according to claim 1 or 6, wherein the frame portion is made of a conductive material, and the insulating layer is interposed between the frame portion and the terminal. The semiconductor device according to the first or sixth aspect of the invention, wherein the frame portion has a concave portion on a surface side of the mounting surface, and the terminal extends from a bottom surface of the concave portion. A flexible printed circuit comprising: a substrate body, providing wiring; and a cover film disposed on the substrate body; wherein the substrate body is mounted with a semiconductor device body; The substrate body may be bent, and includes a mounting surface facing the semiconductor device main body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; and the cover film is disposed on the mounting surface The side covers the through hole. A flexible printed circuit comprising: a substrate body, providing wiring; and a cover film disposed on the substrate body; wherein: the substrate body is mounted with a semiconductor device body; and the substrate body is bendable, including facing the semiconductor a mounting surface on the apparatus main body side, a back surface opposite to the mounting surface, and a through hole penetrating the mounting surface and the back surface; and the cover film is provided on the mounting surface side and includes a diameter opening smaller than the through hole Partially covering the above through holes. The flexible printed circuit according to claim 9 or 10, wherein a spacer layer is further provided on the cover film side on the mounting surface side.